Intermediates for the production of benzotriazoles

ABSTRACT

A compound of the formula: ##STR1## wherein R is a C 1  -C 5  alkyl group, a C 3  -C 5  alkenyl group, a C 3  -C 5  alkynyl group or a C 3  -C 7  cycloalkyl group, which is useful as a herbicide.

This application is a divisional of copending application Ser. No.818,812, filed on Jan. 14, 1986 now Patent No. 4,755,215.

This invention relates to benzotriazoles, and their production and use.More particularly, the present invention relates to novelbenzotriazoles, a process for producing them, and their use asherbicides.

Some benzotriazole derivatives (e.g.4-nitro-1-cyclohexyl-1H-benzotriazole) are known to be effective asherbicides [U.S. Pat. No. 4,240,822]. However, their herbicidal activityis not necessarily satisfactory.

It has now been found that the benzotriazoles of the formula: ##STR2##wherein R is a C₁ -C₅ alkyl group, a C₃ -C₅ alkenyl group, a C₃ -C₅alkynyl group or a C₃ -C₇ cycloalkyl group exhibit a high herbicidalactivity against a wide variety of weeds including broad-leaved weeds,Graminaceous weeds and Cyperaceous weeds in agricultural plowed fieldsby foliar or soil treatment without producing any material phytotoxicityon various agricultural crops such as corn, wheat, rice and soybean.Examples of the broad-leaved weeds are wild buckwheat (Polygonumconvolvulus), pale smartweed (Polygonum lapathifolium), common purslane(Portulaca oleracea), common chickweed (Stellaria media), commonlambsquarters (Chenopodium album), redroot pigweed (Amaranthusretroflexus), radish (Raphanus sativus), wild mustard (Sinapisarvensis), hemp sesbania (Sesbania exaltata), sicklepod (Cassiaobtusifolia), velvetleaf (Abutilon theophrasti), prickly sida (Sidaspinosa), cleavers (Galium aparine), tall morningglory (Pharbitispurpurea), jimsonweed (Datura stramonium), black nightshade (Solanumnigrum), persian speedwell (Veronica persica), common cocklebur(Xanthium pensylvanicum), common sunflower (Helianthus annuus),scentless chamomile (Matricaria perforata), etc. Examples ofGraminaceous weeds are Japanese millet (Echinochloa frumentacea),barnyardgrass (Echinochloa crus-galli), green foxtail (Setaria viridis),large crabgrass (Digitaria sanguinalis), annual bluegrass (Poa annua),blackgrass (Alopecurus myosuroides), oats (Avena sativa), wild oats(Avena fatua), johnsongrass (Sorghum halepense), quackgrass (Agropyronrepens), etc. Examples of the Cyperaceous weeds are rice flatsedge(Cyperus iria), purple nutsedge (Cyperus rotundus), etc.

The benzotriazoles (I) of the present invention are also effective inexterminating, paddy field weeds including Graminaceous weeds such asbarnyardgrass (Echinochloa oryzicola), broad-leaved weed such as commonfalsepimpernel (Lindernia procumbens), indian toothcup (Rotala indicia)and waterwort (Elatine triandra), Cyperaceous weeds such as umbrellasedge (Cyperus difformis) and needle spikerush (Eleocharis acicularis)and others such as monochoria (Monochoria vaginalis) and arrowhead(Sagittaria pygmaea) without producing any phytotoxicity to rice plantson flooding treatment.

In the above formula (I), the term "C₁ -C₅ alkyl group" covers methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, etc.The term "C₃ -C₅ alkenyl group" includes allyl, crotyl group, methallyl,etc. The term "C₃ -C₅ alkynyl group" includes propargyl, 2-butynyl,3-butynyl, 2-pentynyl, 3-pentynyl, etc. Examples of the term "C₃ -C₇cycloalkyl group" are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,cycloheptyl, etc. Among them, preferred are those wherein R is a C₃ -C₅alkenyl group or a C₃ -C₅ alkynyl group. Typical examples of thepreferred compounds are2-[5-fluoro-1-(2-propynyl)benzotriazol-6-yl]-4,5,6,7-tetrahydro-2H-insoindole-1,3-dione,and2-[5-fluoro-1-(2-propenyl)benzotriazol-6-yl]-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione,

The benzotriazoles (I) of the invention are obtained by reacting ananiline of the formula: ##STR3## wherein R is as defined above with anitrite or nitrous ester in an inert solvent in the presence of anaqueous acid at a temperature of 0° to 50° C. for a period of 5 minutesto 4 hours.

The nitrite or nitrous ester may be used in an amount of about 1 to 2equivalents to the aniline (II). Also, the acid may be used in an amountof about 1 equivalent to a large excess to the aniline (II).

As the nitrite or nitrous ester, there may be used sodium nitrite,potassium nitrite, isoamyl nitrite, etc. Examples of the acid arehydrochloric acid, sulfuric acid, acetic acid, etc. Examples of theinert solvent are ethers (e.g. dioxane, tetrahydrofuran), aliphaticacids (e.g. formic acid, acetic acid), water, etc. Their mixtures arealso usable.

After completion of the reaction, the reaction mixture is subjected toan ordinary post-treatment such as extraction with an organic solventand concentration. If desired, any conventional purification proceduresuch as chromatography or recrystallization may be adopted.

A typical example for production of the benzotriazoles (I) isillustratively shown below.

EXAMPLE 1

2-[4-Amino-2-fluoro-5-(2-propynylamino)phenyl]-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione(0.59 g) was dissolved in acetic acid (1.9 ml), and sodium nitrite (0.13g) was added thereto at a temperature of 10° to 15° C. After stirringfor 10 minutes, the reaction mixture was admixed with water andextracted with ethyl acetate. The extract was washed with water and anaqueous solution of sodium bicarbonate, dried and concentrated. Theresidue was purified by silica gel thin layer chromatography using amixture of ethyl acetate and hexane (1:2 by volume) as an eluent to give2-[5-fluoro-1-(2-propynyl)benzotriazol-6-yl]-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione(0.07 g) as a resinous material.

¹ HNMR (CDDl₃, δ): 1.80 (br, 4H), 2.41 (br, 4H), 2.50 (t, 1H, J=2.6 Hz),5.34 (d, 2H, J=2.6 Hz), 7.56 (d, 1H, J=6.0 Hz), 7.73 (d, 1H, J=9.0 Hz).

Some examples of the benzotriazoles (I) produced in the same manner asabove are shown in Table 1.

                  TABLE 1                                                         ______________________________________                                         ##STR4##                     (I)                                             Com-                                                                          pound                                                                         No.   R             State    .sup.1 HNMR (CDCl.sub.3, δ)                ______________________________________                                        1     HCCCH.sub.2   resinous 1.80 (br, 4H), 2.41 (br,                                                      4H), 2.50 (t, 1H, J=2.6                                                       Hz), 5.34 (d, 2H, J=2.6                                                       Hz), 7.56 (d, 1H, J=6.0                                                       Hz), 7.73 (d, 1H, J=9.0                                                       Hz)                                                     ##STR5##     resinous 1.50 (br, 10H), 1.80 (br, 4H), 2.41 (br,                                      4H), 4.55 (m, 1H), 7.43 (d, 1H, J=6.0 Hz),                                    7.73 (d, 1H, J=9.0 Hz)                           3     CH.sub.3 CH.sub.2 CH.sub.2                                                                  resinous 0.98 (t, 3H, J=7.6 Hz),                                                       1.19 (m, 2H), 1.85 (br,                                                       4H), 2.45 (br, 4H),                                                           4.54 (t, 2H, J=7.6 Hz),                                                       7.41 (d, 1H, J=6.0 Hz),                                                       7.77 (d, 1H, J=9.0 Hz)                           4     H.sub.2 CCHCH.sub.2                                                                         resinous 1.82 (br, 4H), 2.43 (br,                                                      4H), 5.1-5.4 (m, 4H),                                                         5.7-6.4 (m, 1H), 7.38                                                         (d, 1H, J=6.0 Hz), 7.74                                                       (d, 1H, J=9.0 Hz)                                5     (CH.sub.3).sub.2 CH                                                                         resinous 1.63 (d, 6H, J=6.6 Hz),                                                       1.85 (br, 4H), 2.45 (br,                                                      4H), 7.35 (br, 1H), 7.47                                                      (d, 1H, J=6.0 Hz), 8.12                                                       (d, 1H, J=9.0 Hz)                                ______________________________________                                    

The aniline (II) as the starting material in the process of thisinvention may be produced according to the following scheme: ##STR6##wherein R is as defined above.

Explaining the reaction at each step in the above scheme, the startingfluoro-acetanilide (III), i.e. 2,5-difluoro-4-nitroacetoanilide, isknown per se [Finger et al.: J. Am. Chem. Soc., 73, 145 (1951); ibid,78, 2593 (1956)], and this is first reacted with 2 equivalents to alarge excess of an amine of the formula:

    R--NH.sub.2                                                (VII)

wherein R is as defined above in an inert solvent (e.g. dioxane,tetrahydrofuran, ethylene glycol dimethyl ether) at a temperature of 50°to 150° C. for a period of 1 to 24 hours to give the amino-acetanilide(IV). Recovery of the amino-acetanilide acetanilide (IV) can beaccomplished by adding water to the reaction mixture, extracting theresultant mixture with an organic solvent and concentrating the extract.When desired, any purification procedure such as chromatography orrecrystallization may be applied.

The amino-acetanilide (IV) is reacted with 2 equivalents to a largeexcess of a mineral acid (e.g. hydrochloric acid, hydrobromic acid) inan inert solvent (e.g. methanol, ethanol, dioxane, water) at atemperature of 20° to 100° C. for a priod of 1 to 24 hours to give thenitroaniline (V). For recovery of the nitroaniline (V), the reactionmixture is distilled under reduced pressure to remove the mineral acidand the solvent, water is added to the residue, and the resultantmixture is neutralized with an alkali, followed by an ordinarypost-treatment such as solvent extraction and concentration. If desired,any conventional purification procedure such as chromatography orrecrystallization may be applied.

Then, the nitroaniline (V) is reacted with 1.0 to 1.1 equivalents of3,4,5,6-tetrahydrophthalic anhydride in an inert solvent at atemperature of 100° to 200° C. for a period of 1 to 48 hours to give thenitrobenzene (VI). As the inert solvent, there may be employed aromatichydrocarbons (e.g. xylene), halogenated hydrocarbons (e.g.chlorobenzene, dichlorobenzene), aliphatic acids (e.g. acetic acid,propionic acid, butyric acid), water or their mixtures. The nitrobenzene(VI) may be recovered from the reaction mixture by adding water thereto,extracting the resultant mixture with an organic solvent andconcentrating the extract. When desired, any purification procedure suchas chromatography or recrystallization may be applied thereto.

The nitrobenzene (VI) is then reacted with 3 to 30 equivalents of ironpowder in the presence of an aqueous acid (e.g. acetic acid, propionicacid) at a temperature of 60° to 150° C. for a period of 1 to 24 hoursto give the aniline (II). As an auxiliary solvent, the reaction systemmay optionally include ethyl acetate or the like. Recovery of theaniline (II) from the reaction mixture may be carried out by extractionwith an organic solvent and concentration, if necessary, followed bypurification such as chromatography or recrystallization.

Some typical examples for preparation of the starting compounds are setforth below.

EXAMPLE 2 Production of the amino-acetanilide (IV)

2,5-Difluoro-4-nitroacetanilide (3.0 g) was dissolved in dioxane (14ml), and propargylamine (2.0 g) was added thereto, followed by heatingunder reflux for 2 hours. The reaction mixture was allowed to cool,admixed with water and extracted with ethyl acetate. The extract waswashed with water, dried and concentrated to give2-fluoro-4-nitro-5-(2-propynyl)aminoacetanilide (1.1 g). m.p., 216°-217°C.

In the same manner as above, the amino-acetanilides (IV) as shown inTable 2 could be produced:

                  TABLE 2                                                         ______________________________________                                         ##STR7##                     (IV)                                            R                  Physical property                                          ______________________________________                                        CH.sub.2 (CH.sub.3).sub.2                                                                        m.p., 146.0-147.0° C.                               CH.sub.2 CH.sub.2 CH.sub.3                                                                       m.p., 138.5-139.0° C.                               CH.sub.2 CHCH.sub.2                                                                              m.p., 155.6° C.                                     CH.sub.2 CCH       m.p., 216-217° C.                                    ##STR8##          m.p., 148.5° C.                                     ______________________________________                                    

EXAMPLE 3 Production of the nitroaniline (V)

2-Fluoro-4-nitro-5-(2-propynyl)aminoacetanilide (3.03 g) was suspendedin a mixture of ethanol (9.4 ml) and conc. hydrochloric acid (2.7 ml),followed by heating under reflux for 2 hours. After removal of ethanoland conc. hydrochloric acid under reduced pressure, water was addedthereto, followed by neutralization with an aqueous sodium bicarbonatesolution. The resultant solution was extracted with ethyl acetate, andthe extract was washed with water, dried and concentrated to give2-fluoro-4-nitro-5-(2-propynyl)aminoaniline (1.41 g). m.p., 189°-190° C.

In the same manner as above, the nitroanilines (V) as shown in Table 3could be obtained.

                  TABLE 3                                                         ______________________________________                                         ##STR9##                     (V)                                             R                  Physical property                                          ______________________________________                                        CH.sub.2 (CH.sub.3).sub.2                                                                        m.p., 121-122° C.                                   CH.sub.2 CH.sub.2 CH.sub.3                                                                       m.p., 114-115° C.                                   CH.sub.2 CHCH.sub.2                                                                              m.p., 111.2° C.                                     CH.sub.2 CCH       m.p., 189-190° C.                                    ##STR10##         m.p., 139.1° C.                                     ______________________________________                                    

EXAMPLE 4 Production of the nitrobenzene (VI)

A mixture of 2-fluoro-4-nitro-5-(2-propynylamino)-aniline (1.41 g) and3,4,5,6-tetrahydrophthalic anhydride (1.33 g) was suspended in aceticacid (7 ml), followed by heating under reflux for 4 hours. The reactionmixture was cooled, water was added thereto, and the resultant mixturewas extracted with ethyl acetate. The extract was washed with water andan aqueous sodium bicarbonate solution, dried and concentrated to give2-[2-fluoro-4-nitro-5-(2-propynylamino)phenyl]-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione(0.85 g). m.p., 183.5° C.

In the same manner as above, the nitrobenzenes (VI) as shown in Table 4could be obtained.

                  TABLE 4                                                         ______________________________________                                         ##STR11##                    (VI)                                            R                  Physical property                                          ______________________________________                                        CH.sub.2 (CH.sub.3).sub.2                                                                        m.p., 139-141° C.                                   CH.sub.2 CH.sub.2 CH.sub.3                                                                       m.p., 158-160° C.                                   CH.sub.2 CHCH.sub.2                                                                              m.p., 143-145° C.                                   CH.sub.2 CCH       m.p., 183.5° C.                                      ##STR12##         glassy                                                     ______________________________________                                    

EXAMPLE 5 Production of the aniline (II)

Iron powder (1.22 g) was suspended in a 5% aqueous acetic acid solution,followed by heating at 80° C. A solution of2-[2-fluoro-4-nitro-5-(2-propynyl)aminophenyl]-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione(0.75 g) in a mixture of acetic acid (2.2 ml) and ethyl acetate (2.2 ml)was dropwise added to the suspension, and the resultant mixture washeated at 70° C. for 3 hours. After removal of the precipitate byfiltration, the filtrate was extracted with ethyl acetate. The extractwas washed with water and an aqueous sodium bicarbonate solution, driedand concentrated to give2-[4-amino-2-fluoro-5-(2-propynyl)amino-phenyl]-4,5,6,7-tetrahydro-2H-isoindole-1,3-dione(0.59 g). m.p., 182.2° C.

In the same manner as above, the anilines (II) as shown in Table 5 couldbe produced.

                  TABLE 5                                                         ______________________________________                                         ##STR13##                    (II)                                            R                  Physical property                                          ______________________________________                                        CH.sub.2 (CH.sub.3).sub.2                                                                        m.p., 41-43° C.                                     CH.sub.2 CH.sub.2 CH.sub.3                                                                       m.p., 185-186° C.                                   CH.sub.2 CHCH.sub.2                                                                              m.p., 148-150° C.                                   CH.sub.2 CCH       m.p., 182.2° C.                                      ##STR14##         glassy                                                     ______________________________________                                    

The above prepared intermediates, i.e. the aminoacetanilide (IV), thenitroaniline (V), the nitrobenzene (VI) and the aniline (II), are noveland can be represented by the general formula: ##STR15## wherein R is asdefined above, R' is an amino group or a nitro group and R" is an aminogroup, an acetamino group or a 4,5,6,7-tetrahydrophthalimido group,provided that when R' is an amino group, R" is a4,5,6,7-tetrahydrophthalimido group. These intermediates are also withinthe scope of the present invention.

In the practical use of the benzotriazoles (I), they may be applied inconventional preparation forms such as emulsifiable concentrates,wettable powders, suspensions and granules in combination withconventional solid or liquid carriers or dilients as well as surfaceactive agents or auxiliary agents. The content of the benzotriazoles (I)as the active ingredient in such preparation forms is usually within arange of 0.05 to 90% by weight, preferably of 0.1 to 80% by weight.Examples of the solid carrier or diluent are fine powders or granules ofkaolin clay, attapulgite clay, bentonite, terra alba, pyrophyllite,talc, diatomaceous earth, calcite, walnut powders, urea, ammoniumsulfate and synthetic hydrous silicate, etc. As the liquid carrier ordiluent, there may be exemplified aromatic hydrocarbons (e.g. xylene,methylnaphthalene), alcohols (e.g. isopropanol, ethylene glycol,cellosolve), ketones (e.g. acetone, cyclohexanone, isophorone), soybeanoil, cotton seed oil, dimethylsulfoxide, N,N-dimethylformamide,acetonitrile, water, etc.

The surface active agent used for emulsification, dispersion orspreading may be any of the anionic and non-ionic type of agents.Examples of the surface active agent include alkylsulfates,alkylarylsulfonates, dialkylsulfosuccinates, phosphates ofpolyoxyethylenealkylaryl ethers, polyoxyethylene alkyl ethers,polyoxyethylene alkylaryl ethers, polyoxyethylene polyoxypropylene blockcopolymer, sorbitan fatty acid esters, polyoxyethylene sorbitan fattyacid esters, etc. Examples of the auxiliary agents includeligninsulfonates, sodium alginate, polyvinyl alcohol, gum arabic, CMC(carboxymethyl cellulose), PAP (isopropyl acid phosphate), etc.

Practical embodiments of the herbicidal composition according to thepresent invention are illustratively shown in the following exampleswherein parts are by weight. The compound number of the activeingredient corresponds to the one in Table 1.

FORMULATION EXAMPLE 1

Fifty parts of Compound No. 4, 3 parts of calcium ligninsulfonate, 2parts of sodium laurylsulfate and 45 parts of synthetic hydrous silicateare well mixed while being powdered to obtain a wettable powder.

FORMULATION EXAMPLE 2

Five parts of Compound No. 1, 14 parts of polyoxyethylenestyrylphenylether, 6 parts of calcium dodecylbenzenesulfonate, 30 parts of xyleneand 45 parts of N,N-dimethylformamide are well mixed to obtain anemulsifiable concentrate.

FORMULATION EXAMPLE 3

Two parts of Compound No. 2, 1 part of synthetic hydrous silicate, 2parts of calcium ligninsulfonate, 30 parts of bentonite and 65 parts ofkaolin clay are well mixed while being powdered. The mixture is thenkneaded with water, granulated and dried to obtain granules.

FORMULTION EXAMPLE 4

Twenty-five parts of Compound No. 3 is mixed with 3 parts ofpolyoxyethylene sorbitan monooleate, 3 parts of carboxymethyl celluloseand 69 parts of water and pulverized until the particle size of themixture becomes less than 5 microns to obtain a suspension.

The benzotriazoles (I) thus formulated in any suitable formulation formare useful for the pre-emergence or post-emergence control of undesiredweeds by soil or foliar treatment as well as flood fallowing treatment.These treatments include the application to the soil surface prior to orafter the transplanting or the incorporation into the soil. The foliartreatment may be effected by spraying the herbicidal compositioncontaining the benzotriazoles (I) over the top of the plants. It mayalso be applied directly to the weeds if care is taken to keep thechemical off the crop foliage.

The benzotriazoles (I) of the present invention may be used togetherwith other herbicides to improve their activity as herbicides, and insome cases, a synergistic effect can be expected. Further, they may beapplied in combination with insecticides, acaricides, nematocides,fungicides, plant growth regulators, fertilizers, soil improvers, etc.

Furthermore, the benzotriazoles (I) can be used as herbicides applicableto agricultural plowed fields as well as paddy fields. They are alsouseful as herbicides to be employed for orchards, pasture lands, lawns,forests, non-agricultural fields, etc.

The dosage rate of the benzotriazoles (I) may vary on prevailing weatherconditions, formulation used, prevailing, season, mode of application,soil involved, crop and weed species, etc. Generally, however, thedosage rate is from 0.02 to 100 grams, preferably from 0.05 to 50 grams,of the active ingredient per are. The herbicidal composition of thepresent invention formulated in the form of an emulsifiable concentrate,a wettable powder or a suspension may ordinarily be employed by dilutingit with water at a volume of 1 to 10 liters per are, if necessary, withaddition of an auxiliary agent such as a spreading agent. Examples ofthe spreading agent include, in addition to the surface active agents asnoted above, polyoxyethylene resin acid (ester), ligninsulfonate,abietylenic acid salt, dinaphthylmethanedisulfonate, paraffin, etc. Thecomposition formulated in the form of granules may be normally appliedas such without dilution.

The biological data of the benzotriazoles (I) as herbicides will beillustratively shown in the following Examples wherein the phytotoxicityto crop plants and the herbicidal activity on weeds were observedvisually as to the degree of germination as well as the growthinhibition and rated with an index 0, 1, 2, 3, 4 or 5, in which thenumeral "0" indicates no material difference is seen in comparison withthe untreated plant and the numeral "5" indicates the completeinhibition or death of the test plants.

The compounds shown in Table 6 below were used for comparison.

                  TABLE 6                                                         ______________________________________                                        Com-                                                                          pound                                                                         No.   Chemical structure     Remarks                                          ______________________________________                                               ##STR16##             U.S. Pat. No. 4,240,822                          B                                                                                    ##STR17##             U.S. Pat. No. 4,240,822                          C                                                                                    ##STR18##             Commercially available herbi- cide;                                           "nitrofen"                                       ______________________________________                                    

TEST EXAMPLE 1

Cylindrical plastic pots (diameter, 10 cm; height, 10 cm) were filledwith upland field soil, and the seeds of Japanese millet, redrootpigweed, tall morningglory and velvetleaf were sowed therein and coveredwith soil. A designated amount of the test compound formulated in anemulsifiable concentrate according to Formulation Example 2 was dilutedwith water, and the dilution was sprayed onto the soil surface by meansof a small hand sprayer at a spray volume of 10 liters per are. The testplants were further grown in a greenhouse for 20 days, and theherbicidal activity was examined.

The results are shown in Table 7.

                  TABLE 7                                                         ______________________________________                                                   Herbicidal activity                                                                                 Tall                                         Compound                                                                              Dosage   Japanese Redroot                                                                              morning-                                                                             Velvet-                               No.     (g/are)  millet   pigweed                                                                              glory  leaf                                  ______________________________________                                        1       40       5        5      5      5                                             10       4        5      4      5                                     3       40       5        5      5      5                                             10       5        5      4      5                                     4       40       5        5      5      5                                             10       5        5      4      5                                     B       40       0        2      0      0                                             10       0        0      0      0                                     C       40       3        3      2      4                                             10       0        1      0      1                                     ______________________________________                                    

TEST EXAMPLE 2

Cylindrical plastic pots (diameter, 10 cm; height, 10 cm) were filledwith upland field soil, and the seeds of Japanese millet, oats, radishand velvetleaf were sowed therein and cultivated in a greenhouse for 10days. A designated amount of the test compound formulated in anemulsifiable concentrate according to Formulation Example 2 was dilutedwith water containing a spreading agent, and the dilution was sprayedover the foliage of the test plants by means of a small hand sprayer ata spray volume of 10 liters per are. The test plants were further grownin the greenhouse for 20 days, and the herbicidal activity was examined.

The results are shown in Table 8.

                  TABLE 8                                                         ______________________________________                                                  Herbicidal activity                                                 Compound                                                                              Dosage  Japanese                Velvet-                               No.     (g/are) millet     Oats Radish  leaf                                  ______________________________________                                        1       10      5          5    5       5                                             2.5     5          4    5       5                                     3       10      5          5    5       5                                             2.5     3          3    4       5                                     4       10      5          4    5       5                                             2.5     4          3    5       5                                     B       10      0          0    0       0                                             2.5     0          0    0       0                                     C       10      3          2    0       3                                             2.5     0          0    0       1                                     ______________________________________                                    

TEST EXAMPLE 3

Wagner's pots (1/5000 are) were filled with paddy field soil, and theseeds of barnyardgrass (Echinochloa oryzicola), broad-leaved weeds (i.e.common falsepimpernel, toothcup, waterwort) and the statoblast of needlespikerush were sowed in 1 to 2 cm depth. Water was poured therein tomake a flooded condition. Buds of arrowhead were sowed in 1 to 2 cmdepth, and rice seedlings of the 3-leaf stage were transplanted therein,and the test plants were grown in a greenhouse. Five days (at that timeweeds began to germinate) thereafter, a designated amount of the testcompound formulated in an emulsifiable concentrate according toFormulation Example 2 and diluted with water (10 ml) was applied to thepots by perfusion, and water was flooded in 4 cm depth. The test plantswere grown for an additional 14 days in the greenhouse, and theherbicidal activity was examined. For two days from the treatment, waterwas leaded with a 3 cm depth per day. The results are shown in Table 9.

                  TABLE 9                                                         ______________________________________                                                   Herbicidal activity                                                                        Barn- Broad-                                          Compound                                                                              Dosage   Rice   yard  leaved                                                                              Needle Arrow                              No.     (g/are)  plant  grass weed  spikerush                                                                            head                               ______________________________________                                        1       1.2      2      5     5     5      5                                          0.3      0      4     5     5      5                                  2       1.2      0      5     5     5      4                                          0.3      0      4     5     5      --                                 A       1.2      0      0     0     0      0                                          0.3      0      0     0     0      0                                  B       1.2      0      0     0     0      0                                          0.3      0      0     0     0      0                                  C       1.2      0      0     1     1      0                                          0.3      0      0     0     0      0                                  ______________________________________                                    

TEST EXAMPLE 4

Vats (33 cm×23 cm×11 cm) were filled with upland field soil, and theseed of soybean, corn, wheat, tall morningglory, velvetleaf, pricklysida, common lambsquarters, sicklepod, johnsongrass and green foxtailwere sowed therein to 1 to 2 cm depth. A deignated amount of the testcompound formulated in an emulsifiable concentrate according toFormulation Example 2 was diluted with water, and the dilution wassprayed onto the soil surface by means of a small hand sprayer at aspray volume of 10 liters per are. The test plants were further grown ina greenhouse for 20 days, and the herbicidal activity was examined.

The results are shown in Table 10.

                                      TABLE 10                                    __________________________________________________________________________              Herbicidal activity                                                                       Tall           Common        Green                      Compound                                                                            Dosage          morning-                                                                           Velvet-                                                                            Prickly                                                                            lambs-                                                                             Sickle-                                                                           Johnson-                                                                           fox-                       No.   (g/are)                                                                           Soybean                                                                            Corn                                                                             Wheat                                                                             glory                                                                              leaf sida quarters                                                                           pod grass                                                                              tail                       __________________________________________________________________________    3     10  0    -- --  5    5    5    5    4   5    5                                2.5 0    -- 0   4    5    4    5    3   4    4                          4     10  1    1  --  5    5    5    5    4   5    5                                2.5 0    0  1   --   4    4    5    3   4    4                          A     10  0    0  0   0    2    1    2    0   3    3                                2.5 0    0  0   0    0    0    1    0   1    0                          B     10  0    0  0   0    0    0    0    0   0    0                                2.5 0    0  0   0    0    0    0    0   0    0                          C     10  0    0  0   0    0    0    0    0   0    0                                2.5 0    0  0   0    0    0    0    0   0    0                          __________________________________________________________________________

TEST EXAMPLE 5

Vats (33 cm×23 cm×11 cm) were filled with upland field soil, and theseeds of corn, wheat, rice plant, tall morningglory, common cocklebur,sicklepod, velvetleaf, hemp sesbania and wild mustard were sowed thereinand cultivated for 18 days in a greenhouse. A designated amount of thetest compound formulated in an emulsifiable concentrate according toFormulation Example 2 was diluted with water containing a spreadingagent, and the dilution was sprayed over the foliage of the test plantsby means of a small hand sprayer at a spray volume of 5 liters per are.The test plants were further grown in the greenhouse for 20 days, andthe herbicidal activity was examined. At the time of the application,the test plants were generally at the 1 to 4 leaf stage and in 2 to 12cm height, although the growing stage of the test plants varieddepending on their species.

The results are shown in Table 11.

                                      TABLE 11                                    __________________________________________________________________________              Herbicidal activity                                                                     Tall                                                      Compound                                                                            Dosage     Rice                                                                             morning-                                                                           Common                                                                              Sickle-                                                                           Velvet-                                                                            Hemp Wild                             No.   (g/are)                                                                           Corn                                                                             Wheat                                                                             plant                                                                            glory                                                                              cocklebur                                                                           pod leaf sesbania                                                                           mustard                          __________________________________________________________________________    1     0.63                                                                              1  1   -- 5    5     4   5    5    5                                      0.16                                                                              1  0   1  4    4     4   5    --   --                               4     0.63                                                                              2  1   1  5    5     4   5    5    4                                      0.16                                                                              1  1   1  4    4     3   4    --   --                               A     0.63                                                                              0  0   0  0    0     0   1    1    1                                      0.16                                                                              0  0   0  0    0     0   0    --   --                               B     0.63                                                                              0  0   0  0    0     0   0    0    0                                      0.16                                                                              0  0   0  0    0     0   0    0    0                                C     0.63                                                                              0  0   0  0    0     0   0    0    0                                      0.16                                                                              0  0   0  0    0     0   0    0    0                                __________________________________________________________________________

What is claimed is:
 1. A compound of the formula: ##STR19## wherein R isa C₁ -C₅ alkyl group, a C₃ -C₅ alkenyl group, a C₃ -C₅ alkynyl group ora C₃ -C₇ cycloalkyl group and R¹ is an amino group or a nitro group. 2.The compound according to claim 1, wherein R is as defined in claim 1,R₁ is an amino group.
 3. The compound according to claim 1, wherein R isas defined in claim 1, R₁ is a nitro group.